Concave hydroplane hull



Get. 5, 1948. w. B. JUTTE CONCAVE HYDROPLANE HULL 3 She ets Sheet 1 Filed Jan.

ATTORNEY INVENTOR.

- WILLIAM B. JUTIE,

n \l... s

Oct. 5, 1948. w. B. JUTTE CONCAVE HYDROPLANE HULL 3 Sheets-Sheet Filed Jan. 8, 1945 l tiilfllltllitilllll WILLIAM B..JUTTE,

INVENTOR.

ATTORNEY Oct. 5, 1948. w. B. JUTTE 2,450,665

CONCAVE HYDROPLANE HULL Filed Jan. 8, 1945 3 Shegts-Sheet 2 WILLIAM B. J 07 75 IN V EN TOR.

ATTORNEY Patented Oct. 5, 1948 UNITED STATES PATENT OFFICE Claims.

This invention relates to an improved concave hyd-roplane hull and more particularly to the hull of a watercraft such as a hydroplane, sea sled, pontoon or the like.

An object of the invention is to provide an improved hull construction for cushioning the pitch of the craft by absorbing the shock of the oncoming sea.

Another object of the invention is to improve the efficiency with which the propelling force of the jet, propeller, or other propelling device is employed to obtain forward thrust of the craft.

Another object of the invention is to provide an improved hull construction which accomplishes both of the above objects and wherein the means which absorbs the shock of the oncoming sea and reduces the former pounding serves also in part to increase the efiiciency with which the forward thrust is applied to the craft,

As a boat or ship moves through or on the surface of water, it displaces the water in a lateral direction with regard to the craft. The craft by its movement has displaced particles by imparting to them movement which is lateral with regard to the craft but both lateral and forward with regard to a fixed point in the water.

According to the present invention, the efficiency with which forward thrust is applied to the craft is increased by applying the propelling force to the laterally-displaced water which is moving forwardly with regard to a fixed point in space, namely, static water. The invention provides an improved hull construction which guides such laterally-displaced water to the propelling means, while preferably serving also to cushion the pitch-of the craft.

As usual in hydropl-an-e action, the reference herein to a hydropl-ane is intended to be descriptive of a boat adapted to move at a speed high enough so that the boat is lifted above its water line at rest by its passage on the surface of the water and substantially all the water it displaces is displaced laterally. According to the present invention, the propelling thrust is applied sub, stantially only on such laterally-displaced water, not on water which is substantially at rest as in common practice. The forward motion of the boat laterally displaces water which moves forward with regard to the sea, and according to the present invention, the propelling thrust is posed heretofore to employ a concave hull, it has the tendency to compound the displaced water of a large wave and then "bump over the hump. Tests of a model of the present invention indicate that the hump is largely eliminated, probably by applyingthe force of propulsion at the point of compounding. Whether this explanation is correct or not, the test showed that the former pounding was replaced by an extremely gentle undulation of the hull and such tests indicate that the hull construction of this invention can reasonably be expected to reduce the pounding of hydroplanes in medium and largesize ships.

The above tests were made of the twin propeller drive, as in Fig. 13. These tests also showed a smoother wake.than heretofore, probably for the reason that in the usual case the boat travels at high speed it leaves at the stern a depres-.- sion in the sea, this depression being filled by the surrounding sea, which spills into it by ravity and resulting in a wave formation in the wake. According to the tests, the wave formation in the wake is reduced in intensity due probably to the fact that the propelling means of the pres-.- ent invention, in acting on the laterally displaced water, returns such water whence it came, and hence, there is a smaller depression in'the sea to be filled by the surrounding sea spilling into it by gravity.

Other objects of the invention are to vary the position where the propelling force is applied to the displaced water, to vary or control a cushion for the shock of the oncoming waves, to provide a construction which lends itself to jet propulsion although screw propellers or other propelling devices maybe employed instead, to use the same jet for propelling a hydroaeroplane on the water and in the air, and to employ jet propulsion for increasing the speed of take-off of a hydro.- aeroplane from the water, and to apply the propelling force to either inboard or outboard moving, laterally-displaced water.

For further details of the invention, reference may be made to the drawings, wherein:

Figure 1 is a longitudinal, sectional view of .the improved hull construction of the present invention.

Fig. 2 is .a bottom plan view of the hull of Fig. 1.

Figs. 3 to 7, inclusive, are sectional views on lines having the corresponding numbers of Fig. 1, looking in the direction of the arrows.

Fig, 8 i a longitudinal, sectional view oi a modified form of hull.

Fig.9 is a bottom plan view of the hull of Fig. '8.

Fig. 10 is a sectional view of a double check valve which may be employed for the vent in the other figures.

Figs. 11, 12 and 13 are cross-sectional views of modifications illustrating various types of propelling devices, the sections having been taken on a line corresponding to line -5 of Fig. 1.

Fig. 14 is a schematic illustration of a hydroaeroplane having the hull of Fig. 1, the section illustrating a vertical section through the fuselage and hull.

Fig. 15 is a view in side elevation of a hydroplane in modified form, wherein the concave hull of this invention is illustrated as an attachment to a conventional boat having a convex hull, with jets to act on laterally-displaced water moving outboard and with means to vary the point of application of the propelling thrust longitudinally of the boat.

Figs. 16, 1'7 and 18 are sectional views on lines of the corresponding numbers of Fig. 15, looking in the direction of the arrows.

Fig. 19 is apartial enlarged sectional view of one side of the hull of Fig. 17.

Fig. 20 is a view looking upward towards one side of the hull on line 2l-20 of Fig. 16, with parts broken away.

Fig. 21 is a sectional view correspondin to Fig. 17 and illustrating a modified apparatus for moving the jets.

Fig; 22 is an enlarged View of one side of the hull of Fig. 21.

Fig. 23 is a View in elevation on line 2323 of Fig. 22, with parts broken away. 7 Referring in detail to the drawings, the watercraft] of this invention is illustrated as a hydroplane, although the improved hull construction of this invention may be applied to a pontoon or other watercraft. The craft I, in effect, is a sea sled 2, under the bow of which is arranged a similar smaller and shorter sea sled 3. The main sea sled 2 has a concave hull 4 which extends the full length of the craft from stem to stem, the curvature of this hull gradually flattening out from stem to stem, as indicated in Figs. 3 to 7. The outer surface of the sides 52, 53 of hull '4 may be vertical, flat and parallel to each other as ,shown in Figs. 3-7. The bottom line of the sides of the hull, an indicated at 5, may extend substantially parallel to the top deck line, as indicated at 6 throughout the major portion of .the length of the craft, except at the bow where th bottom line 5 curves upwardly, as indicated at I to the prow 8, although various other types of superstructure may be employed. Also, the deck 9 which forms the top of hull 4 slopes downwardly from stem to stern whereby the space enclosed between the sides of the hull 4 decreases in height from stem to stem, as indicated in Figs. 3 to 7.

The smaller sea sled 3 fits under the bows of of the concave hull 4. The smaller sea sled 3 also comprises a concave hull i0 which extends from the prow 8'to a point adjacent or forward of amidship,. as indicated at its stem end II. The lateral width of the body of hull I0 preferably decreases from the bow towards the stern and directs or guides the laterally-displaced Water to the. point of propulsion at the stem end II of of hull I0 which is indicated in Fig. 1 as the exhaust tube I2 of a jet propelling device, not shown. .The height of the open space under hull decreases with a corresponding increase in the height of the body of hull ID in a direction 'from'the prow 8 to the stern end II of the sea sled 3. As the height of the body of the I0 increases, the sides of hull I0 become increasingly concave. This is illustrated in Figs. 3 to 5, wherein Fig. 3 shows the sides of hull II! as being straight, as indicated at 40 and M, Fig. 4, showing these sides somewhat concave as indicated at $2 and 43, and Fig. 5 illustrating greater concavity extending over more than a semicircle as indicated at M and 45. The concave surfaces 42 to 4-5 face outboard and cooperate with the adjacent inboard facing concave surface portion of hull A to define a pair of channels 45 and 41 which are laterally open throughout their length on their outboard sides to receive the laterally-displaced water moving inboard indicated by the arrows 48 and $9 in Fig. 5. The water which thus laterally enters the channels 46 and l! passes lengthwise through these channels towards the stem of the craft and is, of course, discharged under the main sea sled 2 at the stern end II of the amziliary sea sled 3. The channels 46 and i? converge in an aft direction and either a single jet I2 may be employed substantially at their point of confluence, as indicated in Figs. 1 and 5, or a separate jet may be employed near the end of each channel, as indicated in Fig. 12. As before stated, the hull It serves to guide the inboard moving, laterally-displaced water indicated by the arrows 48 and 49 lengthwise of the hull It? to a point of propulsion at or adjacent the end H of the hull I0.

Thesides ill-to 5 may be said to provide a double longitudinal step in the concavity of hull 4.

In the various figures, the water line, when the craft is at rest in the water, is indicated by the dot-dash line marked W. L.

As the best position for the point of application of the propelling force varies with the speed of the craft, preferably means are provided for iongitudinally varying the position of the propelling device with respectto the craft. One such means is shown in Fig. 1, wherein the jet exhaust I2 is provided with a slip coupling or expansion joint I3 to permit longitudinal adjustment of the exhaust I2 with respect to the jet engine, which is assumed to be fixed on the ship. Also, the hull I0 is mounted on slides I4 and the hull I0 is held in adjusted longitudinal position by a bolt I5 or the like. The deck is provided with a slot I6 to accommodate movement ofthe bolt 15, and with a slot I? to accommodate movement of the exhaust 12. The mechanism described above for longitudinally shifting the smaller sea sled 3, is purely illustrative, as in actual practice it would, of course, be preferred to have a lead screw or the like to more readily shift the inner hull II) from an operating position on the boat. The best pointof application of the propelling force; that is, the stern II of inner hull I0, varies with the speed and the inner hull should be shifted aft as the speed increases. As before stated, it would, of course, be preferred to have a lead screw or other means to make it more convenient to perform this shifting by an operator on the boat while it is in motion.

A suitable rudder may be provided as indicated at I8, and this rudder may be mounted in and adjacent the rear end of the hull 4, as indicated, the axis of its post being arranged at right angles to the top of the concavity of hull 4, not to the horizon. V

When employing jet propulsion, a certain amount of gas will be discharged by the exhaust I2 and to discharge this gas as well as air (from the foam or water) entrapped by the hull I0, use

may be made of a vent l9 which opens at its lower end intohull 4 adjacent the stem end of exhaust i2. This vent I 9 is particularly useful when employing a hull having a cross step as indicated in'Figs. 8 and 9, as the upper end 2| of the step 20 serves as a pocket to entrap the gas from exhaust 1'2 and the air fromhull I0. A similar pocket 50 exists under the top of h'ull 4 at the end .ll of hull 10.

If desired, the vent i9 may be provided with a conventional hand-operated valve 5|, in order to regulate the flow of air and gas through the vent i9. Under some circumstances this flow may be in one direction and other circumstances it may be in the opposite direction. Such flow may be controlled by a double check valve 22 shown in Fig. -10, wherein the check valve 23 opens only in one direction to permit flow indicated by arrow 24, while the other check valve 25 opens only in the opposite direction to permit flow indicated at 26. The advantage of this arrangement is that while flow in opposite directions is permitted, no flow in either direction is possible until the pressure or suction is great enough to overcome the springs 21 and 28 on the valves. Various other types of double check valves may be employed and suitable means not shown may be employed for adjusting the tension on the springs 21 and 28.

Various other types of propelling devices may be employed. For example, the jet propeller l2 in Fig. 1 may be omitted and the double concave hull construction there shown employed for a pontoon which may be driven by an aerial propeller. Also, instead of the jet propeller of Fig. 1, use may be made of a paddle wheel 29 in Fig. 11, or twin jets 3i] and 3| may be employed on opposite sides of the hull i0 adjacent or in the stem end of channels 46, 41 as in Fig, 12, or twin screw propellers 32 and 33 may be employed on opposite sides of the hull IIJ adjacent or in the stern end of channels 46, 41 as in Fig. 13. In all forms of the invention the hull iii of the smaller sea sled 3 serves not only to cushion the pitch of the craft, but also to direct the laterally-displaced and forwardly-moving water to the propelling device.

In the case of Fig. 13, the laterally-displaced water moves inboard as indicated by the arrows 34 and 35 and the propellers 32 and 33 rotate outboard counter to the flow indicated by the arrows 34 and 35, in order to apply maximum thrust to the water.v This advantage is present whether the auxiliary sea sled 3 is used or not, but its use is preferred.

The inner sea sled 3 or concave hull I0 not only forms a shock absorber by absorbing some of the oncoming seas, but also provides between the two hulls 4 and I0 two spaces, i. e., channels 46, 41 which receive only the water displaced by the bows. As this water has been given lateral motion with respect to the hull, and forward motion with respect to the water through which the hull passes, the propelling means of this invention such as the jet I2, paddle wheel 29, jets 3|! and 3|, and screw propellers 32 and 33 are positioned in the path of this laterally-displaced, forwardly-moving water, whereby the forward thrust of such propelling means on the craft is against that water which is already traveling in the same direction as the craft.

The smaller hull l0 separates the laterally-displaced water from the water which has not been laterally displaced by the craft and in directing such displaced water to the point of propulsion, the smaller hull I0 traps an amount of air in the 6 form of foam which reduces the frictional resistance of the hull. The air cushion thus formed reduces the pounding and the cushioning effect can be adjusted by the valve in Fig. 10 or by a conventional hand-operated valve 5| in the vent i9.

The conventional type of hydroplane is provided with a propeller which frequently is damaged due to collision with drifting objects. This disadvantage is overcome by the use of jet propulsion as indicated in Figs. 1 and '12.

Various modifications may be made in the invention. For example, as schematically indicated in Fig. 14, the superstructure may be that of the fuselage to which is attached the usual wings and rudder, not shown, the craft in this case comprising a hydro-aeroplane. In this case, the jet I2 exerts its force of propulsion on the Water when the hydro-aeroplane is on the Water, and exerts its force of propulsion on the air when the craft is in flight. Also, the channels 45-41 comprise fluid channels which serve to dirent the laterally-displaced water to the jet when the craft is on the water, as above described, these channels also serving to direct air to the jet when the hydro-aeroplane is in flight. The

jet propulsion increases the speed of take off from the water.

In Fig. 15, the boat5|l is a conventional hydroplane to which a modified form of the hull of this invention may be secured as an attachment comprising a concave hull extension 5|, 52 ateach side of the usual convex hull 53 of the boat. Hull 52 is held in position by a bolt 54 which passes through a hole in the main hull 53 and through a slot 55 in the concave hull 52 so that the latter can be shifted lengthwise of the boat. The hull 52 has a jet 56 pointing aft and extending in the channel 51. An expansion joint 58 between the yet 55 and the boat permits the jet to be moved with the hull 52. A jet engine indicated at 59 in Fig. 17, is arranged in the boat. The other hull 5| is similarly constructed. The hulls 5| and 52 receive laterally-displaced water which is moving outboard and the thrust of the jets like 56 is applied to such laterally-displaced outboard moving water. Similar to Fig. 3, as shown in Fig. 19, the hull 52 may be supported for sliding movement on rails such as 60.

As illustrated in Figs. 20 to 23, each hull like 52 with its jet may be shifted lengthwise by means of a pinion 6| and a rack 62. Pinion 6| is mounted on a shaft 53 which extends through the hull and is operated by a suitable handle, not shown. The rack 62 is supported by a slide bearing 54 and is secured to a jet tube 65 which telescopes over an inner jet tube 66, thereby providing an expansion connection for the jet. The rack 32slides through a slot 5! in the top of the concave hull 52. The other hull 5| is, of course, constructed the same as. that shown in Figs. 22 and 23, and is indicated in Fig. 21. In Figs. 21 and 22, the concave hull 52 is sup-ported in an angle frame 38 which is secured by a suitable bracket Bil to the side of the boat 50. In Figs. 21 and 22, the outboard moving, laterally-displaced Water is thrust upon by jet 66 and its companion jet i5 and as the speed of the boat varies, the pinions 6i and i i may be rotated to shift the point of application of the thrust to the water.

I claim:

1. A watercraft having a double concave hull of which one extends substantially from the stem to the stern of said craft with a downwardly facing concavity which decreases in height in a direction from the stem towards the stem, the other of said concave hulls being housed in and arranged under the bows of said first hull and extending from the stem to and terminating substantially amidship, the vertical sides of said other hull becoming increasingly concave in a direction aft from the bow.

2. A watercraft according to claim 1 comprisin propelling means on said watercraft adjacent the stern of said other hull.

3. A watercraft according to claim 1 comprising means providing a pocket above the stern of said other hull, an air vent for said pocket, and means for controlling air flow through said vent.

4. A watercraft according to claim 1 comprising a jet propellin means having an exhaust adjacent the stern of said other hull.

5. A Watercraft according to claim 1 comprising a jet propelling means having an exhaust on the stern of said other hull, an expansion joint for said exhaust, means supporting said other hull for longitudinal adjustment, and means for securing said other hull in adjusted position.

WILLIAM B. JUTTE.

REFERENCES CITED The following references are of record in the file of this patent:

Number Number UNITED STATES PATENTS Name 7 Date Smith Sept. 7, 1880 Hart Sept. 2, 1884 Culbertson Aug. 9, 1898 Pfautz Aug. 10, 1909 Pfautz June 20, 1911 Ryan et a1 Oct. 19, 1915 Hickman Nov. '7, 1916 Graumlich Apr. 16, 1918 Lake Oct. 9, 1923 Baldwin Jan. 17, 1928 Chimang Nov. 8, 1932 Heljesson Feb. 21, 1933 White et a1 Dec. 1, 1936 Apel et al Aug. 9, 1938 Frost Sept. 12', 1939 Willrich, Jr Jan. 13, 1942 FOREIGN PATENTS Country Date Great Britain (1895) "Apr. 18, 1896 Great Britain Jan. 9, 1939 

